Electric-motor load-controlling device



R. CONRADER ELECTRIC MOTOR LOAD CONTROLLING DEVICE Oct. 13, 19251,557,428

Original Filed Dec. l, 1921 3 Sheets-Sheet l @C59 O 0,9 O' f /22 Oct 13l1925 1,557,428 R. CONRADER ELECTRIC MGTOR LOAD CONTROLLING DEVICEoriginal Filed Deo. 1, 1921 s sheets-shea 2 Oct. 13, 1925. 1,557,428

R. CONRADER ELECTRIC MOTOR LOAD CONTROLLING DEVICE original FiledDeo. 1. 1921 :ssheets--sheet MMIII! IIIHII Patented Oct. 13, 1925.

UNITED STATES RUDOLPE'CONRADER, 0F ERIE, PENNSYLVANIA.

ELECTRIC-KOTOR LOAD-CONTROLLING- DEVICE.

Application med December 1, .1921, Serial' No. 519,166. Renewed Hay 6,1925.

To allfwhomitfmuy concern. f

Y Be it known that I, RUDOLPH CONRADER, a citizenof the United States,residingat Erie, in the county of Erie and State of Pennsylvania, haveinvented new and useful Improvements in Electric-Motor Load- ControllingDevices, of which the following is a specification.

In starting electric motor-driven mechanism such as pumps andcompressors lit is desirable with most motors and necessary with some togetthe motor up to speed before subjecting it to its load. The presentinvention is designed to automatically take care of the load as thestarting switch, usually of the rheostat type is operated so that theload is only placed on the motor after it has reached its speed.Preferably the control mechanism is supplemented with a regulator whichwill control the load'in response to variations of pressure especiallywhere the device is usedfon a pump. Details and other features of theinvention will appear from the specification and claims.

The invention-is illustrated in the accompanying drawings as followsFig. 1 is a section on the line 1--1 of the rheostat and controllingvalve.

Fig. 2 a front elevation of the rheostat with the controlling valve insection.

Fig. 3 a side elevation of a pump with the controlling devices attached.Fig. 4 a side elevation, partly in section, fof an unloader.

Fig. 5 a section of an inlet unloader.

.Fig. 6 a side elevation, partly in section, of a pilot valve.

Fig. 7 a section onthe line 7-v-7 in Fig. 6.

Fig. 84 an enlarged view of the spring actuating the switch lever.

1 marks a pump cylinder, 2 a crank shaft from which the pump isoperated, 3 a drive pulley on the crank shaft, 4 an electric motor fromwhich the drive pulley 3 is driven. and 5 the discharge ipe from thepump. The discharge from t e pump leads to the inlet connection 6 of theundloader.

The unloader has a body 7 in which is arranged a-n inlet chamber 8,discharge chamber .9, and unloader chamber 10, lfthe unloader chamberpreferably connecting through a pipe 10 with the inlet of the pump. Apassage 11 connects the inlet chamber 8 with the discharge chamber 9. It

is surrounded by a valve seat 12 on which the valve 14 operates to closethe passage. The valve 14 is carried by a stem 15. A passage 16 connectsthe inlet passage with the unloader passage. The passage' 16 issurrounded by a seat 17 on which an unloader valve 18 operates, theunloader valve being carried by a plunger 19 operating ina cylinder 20.The cylinder is connected by a passage 21 with a control chamber 21. Thespecific formy of unloader forms no part of the invention. In itsoperation the plunger 19l is subjected to the pressure of the controlchamber Which pressure is controlled, the maximum pressure beingordinarily receiver pressure and introduced to the chamber when thereceiver, or receptacle, pressure gets below that desired. Under theseconditions pressure on the plunger closes the valve 18, the face of thevalve being of considerably less area than the plunger so that the twofaces being subjected to the same pressure the dominant pressure on theplunger seats the valve. When it is desired to unload, pressure isexhausted from the chamber 21 and the pressure on the face of the valveopens the. valve and unloads the pump. The stein 15, it will be noted,is subjected at one end to the controlled chamber pressure and at theother end to pressure at the discharge side of the valve 14. Under theseconditions the pressure on this stem is practically balanced while I'thepump is working and the valve 14 open but when the pressure is exhaustedfrom the chamber 21 this unbalances the stem 15 and this elfects,

the closing of the valve 14, thus preventin a return flow of' fluidduring the unloa ing operation. The specific unloader described formsthe subject matter of a companion application, unloader, Serial Number519,164. The controlling switch or rheov stat 22 is provided with theusual arm 23 operating over the contacts 24 of the rheostat. In thefinal position the arm-23 engages an electric magnet 25, the coil ofwhich has the wires c leading from the main wires a and b controllingthe motor. So long as the current is passing to the motor the arm 23 isretained y the magnet. The arm is supplied with the usual coil s ring 23which acting on the arm tends to t row it away from the electric magnet.and to the initial position shown in dash lines which i opens theswitch. This is a common construction the purpose of which is wellunderstood.

It is desirable that with each starting the load lbe taken oill themotor and this is true whether started initially or after a temporarypause in the current. This is accomplished in the present invention asfollows: The controlling valve has the body 25. This body has thecont-rol passage 26 from which a pipe 27 communicates with the4unloader. Ponts 28 and 29 lead from the control paage 26 to the inletpassage 30 and exhaust passage 31 respectively. The inlet paage isconnected by a` pipe 32 with the receiver pipe 9 leading from theIunloader. Valves 34 and 35 control rthe ports 28 and 29. These valvesare supplied with the 'v stems 36 and 37 respectively. The valve body issecured to a frame 38 by means of i a screw 39.- A spring cap 40 isslidingly 'mounted in thev frame. A push pin 41 extends into the cap andrests on the stem 37. A spring 42 rests on the push pin| 41 and isretained in the cap by the plug 43 having a rounded end 44. The @plugnelralizes the spring when the head of the push pin 41 engages fthelower end of the cap but when the cap as a whole is depressed the pushpin is spring-preed against the stem 37, vthus tending -to close thevalve 35. The valve 35 has a small projection 35iL which engages aprojection 34a on the valve 34 so th-at the closing of the valve 35 isaccompanied. by the opening of the valve 34. A cam 45 is arranged on thehub of the arm 23 and engages the plug 43 of the cap 40 and moves thecap so as to reverse the valves with the final movement of the arm toposition turning on the full current and bringing the arm under theinfluence of the magnet 25. A spring 46 operates against vthe stem 36tending to close the valve 34 and to open the valve V35 but this springis of less strength than the spring 42 so that with a depression of thecap 40 a reversal of the valves takes place but upon the release of thecap 40 the valve 34 is closed and the valve 35 is opened. The lower endof the spring 46 rests on a screw 47 by means of which the frame 38issecured on a cap 48 at the top of a supporting pipe 49, the pipe 49being screwed into a Hoor plate 50. By this construction providing theproper length of pipe 49 the device may be applied to the switch ofordinary installations without change of that installation such as isordinarily mounted on the wall as indicated in Fig. 3.

The .operation of the mechanism so far as described is as follows: Withthe arm '23 initially open and the .switch open the though there ispressure in the receiver there is no pressure carried by way of the ipe27 to the controlling chamber 21 of t e unloader and the unloader is inunloading position. As the arm 23 is moved forward turningfthe currentinto the motor, the motor is started with the unloaded ump and 'i as itprogresses in its speed and t e control lever is advanced the controllever finally reaches a place near its ultimate position bringing thecam 45 into engagement with the cap 40 and with the final movementreversin the valves 'and bringing the arm 23 un er the influence of themagnet 25 so that as the operator releases the arm 23 it is held by themagnet 25 against the spring 23a. With a reversal of the valves in thisfinal movement air is turned through the port 28 and the exhaust isclosed. The air reaching the control chamber Voperates on the plunger 19closing the valve 18, thus cutting out the unloader` and the pump`starts to work. If, for any reason the switch is thrown by cutting offthe current or through the operator the cam 45 is moved away from thecap 40, thus releasin the cap and the valves are reversed throug ltheaction of the spring 46. Upon the opening of the exhaust valve air isexhausted from the control chamber thus unloading the pump so that witha starting of the motor the pump starts unloaded.

. It is desirable to supply the unloader with a pilot valve, orregulator responsive to pressure so that after the motor is startedthepump may unload and load in response to pressure requirements. I haveprovided such a ilot valve (the pilot valve forming the sub]ect matterof a companion application Serial Number 519,163, pressure controlledvalve' mechanism), or regulator as follows:

' A valve body 55 is screwed into the chamber 21. This body has thecontrol passage 56 connected by the orts 57 and 58 with the inletpassage 59 an exhaust passage 60 respectively. The passage 59 has a pipecon- 1 nection 61 and the passage 60 the pipe connection 62. The pipeconnection 61 has the pipe 27 leading to it from the controlling valve.A valve 63 controls the port 57 and the valve 64 the port 58. Stems 65and* 66 extend from the valves respectively. These stems are secured tothe cross heads 67. Springs 68 extend from the ends of the cross headsto the valve body and tend to close the valves 63 and 64. Projections 69en x the cross heads 67, the projections extending from a yoke 70. Theyoke .70 has an opening 71 into which one end of a bell crank 72extends. The bell crank is mounted on a pin 73 and is connected by alink 74 with a lever 75. The leverl 75 is mounted on a pin 76. A bearingpoint 77 is carried by a diaphragm. 78 and extends into a detent in thelever and communicates the movement of the diaphragm to the lever. Thediaphragm is mounted in a diaphragm plate 7 9, the diaphragm beingclamped on said plate by the cover 80. A passage 81 extends through thediaphragm plate communicating with the inlet passage 59 so that when theinlet or control valve is open the diaphragm is subjected to receiver orpump pressure. A screw-threaded projection 82 is arranged on the coverand a follower 83 is screwed into this projection. Aspring'84 is engagedby the follower and rests on a base plate 85 having a point extendinginto a detent in the lever 75, the spring opposing the movement of thediaphragm under pressure in the well-known manner. The operation oi thepilot valve is as follows: l-Vhen the receiver pressure rises above thepredetermined pressure the diaphragm is moved carrying with it the lever75 to the left. This closes the inlet valve 63 and opens the exhaustport 64, thus exhausting the air from the control chamber and from theback of A the plunger 19. This allows the valve 18 to open, thusunloading the pump in the manner hereinbefore described. On a-reductionof pressure o n the diaphragm the spring 84 moves the lever in theopposite direction closing the exhaust valve and opening the inletvalve, thus putting pressure on the control chamber and through thepressure on the plunger closing the valve 18 and subjecting the pump topumping action.

It is desirable to vary lthe range of variation in pressure between theunloading and loading up of the pump and this is accomlished with thisregulator as follows: The lever 75 has a V-shaped cam 86 which isengaged by a V-shaped cam 87. The cam 87 is carried by a lever 88. Thelever 88 is mounted on a pin 89 carried by the diaphragm plate 79. A pin90 extends from the cover plate through the lever. A spring 91 isarranged on the pin and a nut 92 exerts pressure on the spring. Theoperation of this device is as follows: With the initial movement ineither direction the cam 87 assists in the resistance to the movement ofthe lever 75 but after the lever passes the intermediate point the cam87 assists the movement. Consequently there is resistance to a reversal.The amount of resistance may be varied by adjusting the spring 91 by thenut 92 and the range of variation required to ell'ect the reversal maybe thus enlarged or reduced.

This device may be adapted to an un.

valve has the 96 and is normally closedv by a spring 97. A plunger 98 ismounted in the cylinder 99. The plunger has an extension 100 engagingthe stem 96. Aspring 101 returns the plunger and relieves the stem 96 sothat the'valve may be closed. A pipe 102 extends to the regulatorpassage 56. The regula-tor or pilot valve is provided with a passage 103in which there is a screw plug 104 when the device is operating on theunloader shown in Fig. 4. With an unloader operating with pressure thescrew plug 104 is placed in the passage 81 and the valves are connectedup as follows: .The pipe 32 carrying the receiver .pressure is connectedto the passage 31 instead of the passage 30 and also connected direct topassage 59 and the vcontrol passage 26 is connected to the passage 59.The passage 30 is open to the atmosphere. Under these conditions at thestart of the operation the valve 35 is open and the valve 34 closedTherefore pressure is delivered by way of the passage 26 and the passage59. If the receiver pressure on the diaphragmthrough the connection tothe passage 60 is less than the predetermined pressure the valve 63which is normally the exhaust valve of the regulator will be open 'so asto load up the compressor but under the present conditions inasmuch asthis exhaust is connected by way of the passage 26 and valve 35 with thepressure, pressure is delivered through this passage to back of theplunger 98 and the compressor is unloaded during this interval. If thepressure on the diaphragm is above the pre-determined pressure the valve63 will be closed and the valve 64 opened and inasmuch as the passage 60is at all times under receiver pressure, receiver pressure will pass bythe valve 64 to the unloader and unload it so that with any yconditionof pressure in the receiver the unloader will be brought to untor. enthe cam '45 operatesto close the valve 35 and open the valve 34 theunloader will continue in its unloading position, or will load up thecompressor depending on the receiver pressure. If the receiver pres-Asure is below the desired pressure and this pressure is communicated tothe diaphragm the valve 63 will be open and the valve 34 at this timebeing also open there is a direct exhaust from the cylinder 99 by wav ofthe valve63, 'passage26 and valve 34. lf, however, the receiver pressureis above thev desired pressure the -valve 63 will be closed and thevalve 64 o ned, thus continuing the pressure on the pIlleinger 98 andcontinuing the compressor in loaded condition.

While I have shown a rheostat which inbroader phases' of my invention jIwish`tcA loadingvposition with the starting of the mo- Y I volves adevice for making and breaking the device, the combination of anelectricmotor- .include any device for making and breaking the currentand have designated such a device a switch desiring to include by thisdesignation any device which will control e the circuit. v

What I claimas new is 1. In an electric motor load controllin device,the combination of an electric motor manually actuated variableresistance controlling switch; an unloader; and means ac tuated 'as theswitch is actuated for actuat ing the unloader.

controlling switch; a pressure actuatedunloader; a valve devicecontrolling the unloader comprising connected control, inlet and exhaustpassages, valves controlling said connections; and means acted on by the`switch as the switch is actuated for-actuating said valves alternatelytov` control the unloader.

i 4. In an electric motor load controlling device,.the combination of anelectric motor controlling switch,- a pressure actuated unloader; avalve device comprising connected control, inlet and exhaust passages;opposing valves controlling said connections; op-

: posing springs tending to closesaid valves,

one of said springs having greater strength than the other; means forneutralizlng the dominant spring; and means acting as the switchisactuated for actingon the dominant sprin to actuatethe valves to controlthe unloa er.

,- 5. In an electric motor load vlcontrolling device, the combinationoan electric motor controlling rheostat having a series of contacts andan arm successively operating on sald contacts; a pressure-actuatedunloader;

a valve device controlling the unloader com;

prising connected control, inlet and exhaust passages; opposing valvescontrolling said connections; opposing lsprings tending to close saidvalves, one of said springs having greater strength than the other;means for neutralizing the .dominant spring; and a cam on the 4armact-ing on the dominant spring to reverse the valves to actuatethevalves to actuate the unloader.- 6.. In an -electric motor load-controlling device, the combination. of an electric motor controllingrheostat; comprising'a series of contacts and an'arm` operating oversaid by the arm for actuating the unloader as the l contacts; anunloader; `and devices carried arm is actuated.

. 7.' In an electric motor load controlling device, the combination ofan electric motor4 controlling rheostatl comprising a series of contactsandan arm operating over the same; a pressure-actuated unloader; a valvecontrolling the 'unloader; and means comprising a cam carried by the armfor actuating the valve.

8. In an electric motor load controlling device; the combination of anelectric motor controlling switch; electro-magnetic means for holdingthe switch in closed position; means opening the switch on a reductionof current in the circuit controlled by the switch; an unloader; andmeans actuated as the switch is actuated to open or close the switchactuating the unloader.

9. In an electric motor load `controlling device, the combination of anelectric motor controlling switch;` electro-magnetic means holding theswitch in'closed position; .means opening the switch on a reduction ofthe current in the circuit controlled by the` switch; a pressureactuated unloader; a valve controlling the pressure on the unloader tocontrol the unloader; and means actuated as -the switch is actuatedeither closing or opening actuating the valve.

1 0. In an electric motor load controlling device, the combination of anelectric motor controlling switch; an unloader; means actuated as theswitch is actuated controlling the unloader; and a pressure actuateddevice controlling the unloader, said pressure actuated device operatingindependently of an action of the switch.

11. In an electric motor .load controlling device, the -combination ofan electric motor controlling switch; a pressure-actuated -unloader; avalve controlling the unloader; means actuated as the switch is actuatedcontrolling the valve; and a pressure-actuated valve controlling theunloader.

controlling switch; a -pressureactuated unloader; a valve controllingthe unloader;

means actuated as the switch is actuated controlling the valve; andapressure-actuated valve controllin' the unloader, said pressure-actuatedva ve operating independently of the action of the valvecontrolled bythe switch.

12. In an electric motor load controllingl device, the combination of anelectric motor sol 13. In an electric.motor load controlling device, thecombination-fof an electric motor controlling switch; anelectro-magnetic reduction ,of the current controlledby the switch; anunloader; means'actua'ted as the switch is actuated to open or close thesame controlling the unloader; and a pressureactuated device actuatingthe'unloader.

14. In an electric motor lead controlling device, the combination ofan-electric motor controlling` switch;l an electro-magnetic 'means forholding the switch in closed position; means for opening the switch upona means for holding the switch in closed position; means for opening theswitch upon a reduction of the current controlled by the switch; anunloader; means actuated as the switch is actuated to open or close thesamecontrolling the unloader; and a pressureactuated device actuatingthe unloader, said pressure'controlled device acting independently ofthemeans controlled by the` switch.

15. In an electric motor load controlling device, the combination of aypressure-actuated unloader; a regulating valve controlling saidunloader comprising a control passage, an exhaust passage, and anl inletpassage; connections between the exhaust and inlet passages and thecontrol passage; valves controlling said connections; a motor subjectedto pressure actuating said valves; a control valve comprising a controlpassage, and exhaust and inlet passages; connections between the inletand exhaust passages and the control passage; control valves'controlling said connections; a connection between the control passageof thecontrolling valve and the inlet passageof the reglatmg valve; aswitch controlling the electric motorr; and means actuating saidcontrolling valves as the switch is actuated. v

16. In an electric motor load controlling device, the combination ofanelectric motor; a controlling switch actuated by a lever; a springoperating on the lever tending to open the circuit; an electro-magneticdevice normallyholding the lever in closed position; an unloader; andmeans actuated as the lever is actuated for actuating the unloader.

17. In an electric motor load controlling device, the combination of anelectric motor; a controlling'switch actuated by a lever; a springoperating on the lever tending to open the circuit; an electro-magneticdevice normally holding the lever'ini closed position; an unloader;means ,actuated as the lever is actuated for actuating the unloader; anda cam mechanism comprising an element carried by the lever for actuatingthe unloader.

In testimony whereof I have hereunto set my hand. g'

RUDOLPH co-NRADER.

